When it was proposed that Error Code 418 I'm a Teapot be removed from Golang, Node and ASP.NET, a campaign to save it was quickly launched - and almost instantly successful.

We are all familiar with the 404 error code for "not found" and also 403 "forbidden". But you've may never have come across a 418 "I'm a teapot" error in the wild.

It dates from 1998 when it originated as part of a more elaborate April Fool's Day joke, Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0), from Larry Masinter of the Internet Engineering Task Force (IETF), which sets Internet standards, and subsequently found its way into ASP.NET, Node.js and Google's Go as an Easter Egg.

Last week Mark Nottingham, mnot on GitHub where he is an active contributor and who states in his profile that he works on HTTP specifications and implementations, opened issues on three repos, relating to Golang, Node.js and ASP.NET requesting the removal of support for 418. In each he sketches the history and makes the same case for removal:

HTCPCP was an April 1 joke by Larry to illustrate how people were abusing HTTP in various ways. Ironically, it's not being used to abuse HTTP itself -- people are implementing parts of HTCPCP in their HTTP stacks.

While we have a number of spare 4xx HTTP status codes that are unregistered now, the semantics of HTTP are something that (hopefully) are going to last for a long time, so one day we may need this code point.

Please consider removing support for 418 from Go HTTP, since it's not a HTTP status code (even by its own definition). I know it's amusing, I know that a few people have knocked up implementations for fun, but it shouldn't pollute the core protocol; folks can extend Go easily enough if they want to play with non-standard semantics.

On each repo there was quite a flurry - with far more thumbs down votes than thumbs up. It was 15-year old Shane Brunswick who created the Save 418 Movement arguing:

The application of such an status code is boundless.

Its utility, quite simply, is astonishingly unparalleled.

It’s a reminder that the underlying processes of computers are still made by humans. It'd be a real shame to see 418 go.

The pressure worked and the outcome is that far from being removed the status of 418 has being changed to "Reserved" thanks to a draft document filed by Mark Nottingham to the IETF.